Autonomous vehicles may be equipped with various sensors and control arrangements which allow such a vehicle to drive autonomously. The sensors may for example be camera-sensors, radar-sensors and/or lidar-sensors. The sensors are arranged to continuously monitor the surroundings of the host vehicle in order to gather information on an upcoming road section. Such information may relate to a direction and/or gradient of the road section, road markings, traffic lanes, traffic signs, various climate and weather conditions etc. The sensors are generally also configured to detect positions, velocities and directions to surrounding vehicles on or near the road section.
Control/drive arrangements of the host vehicle may be configured to control the host vehicle in accordance with input from the sensors. The control arrangement or subsystems thereof may for example be arranged to control a direction and a velocity of the host vehicle. The control arrangement or subsystems thereof may also be configured to control distances between the host vehicle and surrounding vehicles, or distances to road markings. The control arrangements may include a number of co-operating systems, such as adaptive cruise control, lane-keeping-aid and emergency brake assist systems.
When the autonomous vehicle drives along a route on a road, a situation may arise wherein the autonomous vehicle catches up another slower vehicle which is driving along the same route in the same direction as the host vehicle. In case the road has at least two lanes for travel in the same direction, the autonomous vehicle may change lane in order to overtake the slower vehicle in an adjacent lane. If the autonomous vehicle is catching up a slower vehicle on a road with only one lane for travel in each direction, or on a road with a broad common lane for two different directions of travel, control arrangements or drive systems of the autonomous vehicle may be configured to overtake the slower vehicle ahead using a lane, or part of a lane, which is normally used by oncoming vehicles, travelling in the opposite direction.
During relatively straight road sections, where sensors in the autonomous vehicle may monitor the road well ahead of the autonomous vehicle, overtake of a slower vehicle ahead may be relatively easy. During less favourable circumstances, it may be more hazardous to overtake a preceding vehicle.
In a potential overtake scenario, where the autonomous vehicle approaches a slower preceding vehicle, it may be very difficult to assess how much time that is gained during the drive to a host vehicle destination if an overtake is performed, compared to if the host vehicle stays behind the slower vehicle. This uncertainty may lead to a situation where overtaking is performed albeit the time gained is small or insignificant. In addition, if the sensors that monitor the vehicle surrounding fail to detect that it, e.g. due to intense traffic, may be difficult for the autonomous vehicle to return to its lane, a situation may arise when an operator has to manually take control over the vehicle.
Thus, improvements in the field of overtaking assessment for autonomous vehicles in potential overtaking scenarios are desirable.